Municipalities have extensive networks of piping for controlling the flow of water from storage and pumping stations to users. The network of piping includes numerous valves such that portions of the network can be closed off as needed for service while the remainder of the network remains in operation. The piping required for such networks can range in size from as small as three or four inches in diameter to as large as three feet in diameter. The piping and the valves of the water system are located below ground and extend throughout the community.
When one of the pipes of a water system fails or changes are made to the distribution network, municipal personnel first isolate a section of piping. One or more valves may be opened or closed to shut down water passing through the affected portion of piping. Thereafter, ground is removed from above, around and under the pipe and the pipe is cut to remove the defective area or install new distribution features (valves or branches). Thereafter, replacement pipes and components are cut and fit into the pipeline void left from the removed section.
Currently, hand held rotary saws are employed to cut pipe in the field for making repairs for municipal water systems. Such hand held rotary saws, however, are dangerous to the operator. Frequently, metal pieces broken loose during the cutting process are tossed into the arms and face of the operator or the cutting media becomes pinched from the compressive loads of the pipeline; the physical limitations of the operator are inadequate to prevent the tool from bucking and becoming a people cutting projectile. It is not uncommon for water system personnel to have scars from injuries incurred as a result of repairing the pipes thereof.
As can be seen, there is a need for an improved saw for use by personnel of water systems, that maintains the desirable features of speed and weight, but safeguards the operator by limiting uncontrolled motion and guarding the cutting media for cutting pipe in the field.